makes it possible to compile libzstd in single-thread mode without zstdmt_compress.c (#819)

NEWS

@@ -3,6 +3,7 @@ license : changed /examples license to BSD + GPLv2
 license : fix a few header files to reflect new license (#825)
 fix : 32-bits build can now decode large offsets (levels 21+)
 fix : a rare compression bug when compression generates very large distances (only possible at --ultra -22)
+build: fix : no-multithread variant compiles without pool.c dependency, reported by Mitchell Blank Jr (@mitchblank) (#819)
 build: better compatibility with reproducible builds, by Bernhard M. Wiedemann (@bmwiedemann) (#818)
 
 v1.3.1

circle.yml

@@ -9,7 +9,7 @@ dependencies:
 test:
   override:
     - ? |
-        if [[ "$CIRCLE_NODE_INDEX" == "0" ]]                                    ; then cc -v; make all   && make clean; fi &&
+        if [[ "$CIRCLE_NODE_INDEX" == "0" ]]                                    ; then cc -v; make all   && make clean && make -C lib libzstd-nomt && make clean; fi &&
         if [[ "$CIRCLE_NODE_TOTAL" < "2" ]] || [[ "$CIRCLE_NODE_INDEX" == "1" ]]; then make gnu90build   && make clean; fi
       :
         parallel: true

lib/.gitignore

@@ -1,2 +1,3 @@
 # make install artefact
 libzstd.pc
+libzstd-nomt

lib/Makefile

@@ -101,10 +101,19 @@ lib-release lib-release-mt: DEBUGFLAGS :=
 lib-release: lib
 lib-release-mt: lib-mt
 
+# Special case : building library in single-thread mode _and_ without zstdmt_compress.c
+ZSTDMT_FILES = compress/zstdmt_compress.c
+ZSTD_NOMT_FILES = $(filter-out $(ZSTDMT_FILES),$(ZSTD_FILES))
+libzstd-nomt: LDFLAGS += -shared -fPIC -fvisibility=hidden
+libzstd-nomt: $(ZSTD_NOMT_FILES)
+	@echo compiling single-thread dynamic library $(LIBVER)
+	@echo files : $(ZSTD_NOMT_FILES)
+	@$(CC) $(FLAGS) $^ $(LDFLAGS) $(SONAME_FLAGS) -o $@
+
 clean:
 	@$(RM) -r *.dSYM   # Mac OS-X specific
 	@$(RM) core *.o *.a *.gcda *.$(SHARED_EXT) *.$(SHARED_EXT).* libzstd.pc
-	@$(RM) dll/libzstd.dll dll/libzstd.lib
+	@$(RM) dll/libzstd.dll dll/libzstd.lib libzstd-nomt*
 	@$(RM) common/*.o compress/*.o decompress/*.o dictBuilder/*.o legacy/*.o deprecated/*.o
 	@echo Cleaning library completed
 

lib/compress/zstd_compress.c

@@ -112,23 +112,37 @@ size_t ZSTD_freeCCtx(ZSTD_CCtx* cctx)
     cctx->workSpace = NULL;
     ZSTD_freeCDict(cctx->cdictLocal);
     cctx->cdictLocal = NULL;
+#ifdef ZSTD_MULTITHREAD
     ZSTDMT_freeCCtx(cctx->mtctx);
     cctx->mtctx = NULL;
+#endif
     ZSTD_free(cctx, cctx->customMem);
     return 0;   /* reserved as a potential error code in the future */
 }
 
+
+static size_t ZSTD_sizeof_mtctx(const ZSTD_CCtx* cctx)
+{
+#ifdef ZSTD_MULTITHREAD
+    return ZSTDMT_sizeof_CCtx(cctx->mtctx);
+#else
+    (void) cctx;
+    return 0;
+#endif
+}
+
+
 size_t ZSTD_sizeof_CCtx(const ZSTD_CCtx* cctx)
 {
     if (cctx==NULL) return 0;   /* support sizeof on NULL */
     DEBUGLOG(5, "sizeof(*cctx) : %u", (U32)sizeof(*cctx));
     DEBUGLOG(5, "workSpaceSize : %u", (U32)cctx->workSpaceSize);
     DEBUGLOG(5, "streaming buffers : %u", (U32)(cctx->outBuffSize + cctx->inBuffSize));
-    DEBUGLOG(5, "inner MTCTX : %u", (U32)ZSTDMT_sizeof_CCtx(cctx->mtctx));
+    DEBUGLOG(5, "inner MTCTX : %u", (U32)ZSTD_sizeof_mtctx(cctx));
     return sizeof(*cctx) + cctx->workSpaceSize
            + ZSTD_sizeof_CDict(cctx->cdictLocal)
            + cctx->outBuffSize + cctx->inBuffSize
-           + ZSTDMT_sizeof_CCtx(cctx->mtctx);
+           + ZSTD_sizeof_mtctx(cctx);
 }
 
 size_t ZSTD_sizeof_CStream(const ZSTD_CStream* zcs)
@@ -238,10 +252,6 @@ static ZSTD_CCtx_params ZSTD_assignParamsToCCtxParams(
         return ERROR(parameter_outOfBound);  \
 }   }
 
-size_t ZSTDMT_CCtxParam_setMTCtxParameter(
-    ZSTD_CCtx_params* params, ZSTDMT_parameter parameter, unsigned value);
-size_t ZSTDMT_initializeCCtxParameters(ZSTD_CCtx_params* params, unsigned nbThreads);
-
 size_t ZSTD_CCtx_setParameter(ZSTD_CCtx* cctx, ZSTD_cParameter param, unsigned value)
 {
     if (cctx->streamStage != zcss_init) return ERROR(stage_wrong);
@@ -379,16 +389,25 @@ size_t ZSTD_CCtxParam_setParameter(
         if (value == 0) return 0;
 #ifndef ZSTD_MULTITHREAD
         if (value > 1) return ERROR(parameter_unsupported);
-#endif
+#else
         return ZSTDMT_initializeCCtxParameters(params, value);
+#endif
 
     case ZSTD_p_jobSize :
+#ifndef ZSTD_MULTITHREAD
+        return ERROR(parameter_unsupported);
+#else
         if (params->nbThreads <= 1) return ERROR(parameter_unsupported);
         return ZSTDMT_CCtxParam_setMTCtxParameter(params, ZSTDMT_p_sectionSize, value);
+#endif
 
     case ZSTD_p_overlapSizeLog :
+#ifndef ZSTD_MULTITHREAD
+        return ERROR(parameter_unsupported);
+#else
         if (params->nbThreads <= 1) return ERROR(parameter_unsupported);
         return ZSTDMT_CCtxParam_setMTCtxParameter(params, ZSTDMT_p_overlapSectionLog, value);
+#endif
 
     default: return ERROR(parameter_unsupported);
     }
@@ -2531,16 +2550,6 @@ size_t ZSTD_compressStream(ZSTD_CStream* zcs, ZSTD_outBuffer* output, ZSTD_inBuf
     return ZSTD_compressStream_generic(zcs, output, input, ZSTD_e_continue);
 }
 
-/*! ZSTDMT_initCStream_internal() :
- *  Private use only. Init streaming operation.
- *  expects params to be valid.
- *  must receive dict, or cdict, or none, but not both.
- *  @return : 0, or an error code */
-size_t ZSTDMT_initCStream_internal(ZSTDMT_CCtx* zcs,
-                    const void* dict, size_t dictSize, ZSTD_dictMode_e dictMode,
-                    const ZSTD_CDict* cdict,
-                    ZSTD_CCtx_params params, unsigned long long pledgedSrcSize);
-
 
 size_t ZSTD_compress_generic (ZSTD_CCtx* cctx,
                               ZSTD_outBuffer* output,

lib/compress/zstd_compress.h

@@ -16,7 +16,9 @@
 *  Dependencies
 ***************************************/
 #include "zstd_internal.h"
-#include "zstdmt_compress.h"
+#ifdef ZSTD_MULTITHREAD
+#  include "zstdmt_compress.h"
+#endif
 
 #if defined (__cplusplus)
 extern "C" {
@@ -90,7 +92,9 @@ struct ZSTD_CCtx_s {
     ZSTD_prefixDict prefixDict;   /* single-usage dictionary */
 
     /* Multi-threading */
+#ifdef ZSTD_MULTITHREAD
     ZSTDMT_CCtx* mtctx;
+#endif
 };
 
 

lib/compress/zstdmt_compress.h

@@ -108,6 +108,22 @@ ZSTDLIB_API size_t ZSTDMT_compressStream_generic(ZSTDMT_CCtx* mtctx,
                                                 ZSTD_EndDirective endOp);
 
 
+/* ===   Private definitions; never ever use directly  === */
+
+size_t ZSTDMT_CCtxParam_setMTCtxParameter(ZSTD_CCtx_params* params, ZSTDMT_parameter parameter, unsigned value);
+
+size_t ZSTDMT_initializeCCtxParameters(ZSTD_CCtx_params* params, unsigned nbThreads);
+
+/*! ZSTDMT_initCStream_internal() :
+ *  Private use only. Init streaming operation.
+ *  expects params to be valid.
+ *  must receive dict, or cdict, or none, but not both.
+ *  @return : 0, or an error code */
+size_t ZSTDMT_initCStream_internal(ZSTDMT_CCtx* zcs,
+                    const void* dict, size_t dictSize, ZSTD_dictMode_e dictMode,
+                    const ZSTD_CDict* cdict,
+                    ZSTD_CCtx_params params, unsigned long long pledgedSrcSize);
+
 
 #if defined (__cplusplus)
 }